The invention refers to an unwinding system, which serves the purpose of improving the conditions for the handling of large reels of tissue in processes involving the application of this kind of material, for example in the formation of small rolls. Tissue is a laminar material of extremely fine paper, used to manufacture, for example, rolls of toilet paper, rolls of kitchen paper and such like.
The rolls of tissue paper may consist of one or two plies. During the manufacturing stage the initial web is completely smooth, to which and in certain cases a specific corrugated effect is applied, which is how it is finally marketed.
The nature of this material means that, during its processing in the formation of the rolls, the web should not be subject to major stresses, as this will lead to the loss of the corrugated effect. Furthermore, the rolls for toilet paper and the like are sold in different sizes and diameters; which means that by subjecting the corresponding web, during the formation of the rolls, to greater or lesser tension a variable compaction of the rolls will be achieved, even allowing for different lengths of the roll-forming web to be applied to rolls of the same diameter.
In order to suitably control the compaction of the rolls, so that they include a pre-established length of web, the roll-forming web must be fed under controlled conditions of tension. This must be combined with an infeed speed that renders the production profitable.
The process for forming the aforementioned rolls is based on the infeed of the web from a large reel which exceeds two metres in diameter, from which the laminar web of tissue is unwound in order to form the commercial rolls, with one or two plies of laminar material, in such a way that when the infeed reel runs out it can be replaced by another for continuing the process.
According to a traditional solution, the infeed reel for the laminar roll-forming web is mounted on a system of belts, much like a bed. These belts are drive belts, whereby their movement rotates the reel mounted on them, thus unwinding the reel. When the end of the reel is reached the drive is halted, bringing the process to a stop for the replacement of the reel and the splicing of the new reel onto the web supplying the process.
The splicing of the new reels for continuing supplying the process may be by tying, gluing or any other traditional solution. This operation is always performed manually, as the tests and trials for automation that have been effected to date have not provided satisfactory results given the nature of the laminar tissue material, which has a very low tensile strength, so that it breaks easily when subjected to high stresses. This material is also very flexible, which makes automatic cutting difficult.
Splicing the new reels manually when the infeed reel runs out, with the consequent halt in the production process, means the inconvenience of a low-performance process due to the stoppages for replacing the reels, with the consequent decelerations and accelerations of the supply of the laminar web in said stoppages, in addition to the time required for the actual splicing operation itself.
The drive system for unwinding using motorised belts entails furthermore a series of drawbacks stemming from the very nature of this system, as for example:                The rubbing of the belts against the reel to be driven generates a large amount of dust, with a high risk of fire.        The wear on the belts and their moving assembly parts means that considerable maintenance is required.        The control of the unwinding is largely inaccurate, which is reflected in the results.        The wear on the belts through the rubbing against the reels means that they need to be replaced frequently, at significant financial expense.        The direct contact between the infeed reel and the belts driving the unwinding represents an unfavourable hygienic circumstance with regard to the laminar web, especially when taking into account the applications for which it is destined.        The whole installation occupies a large area, as in addition to the support belts for the reels feeding the laminar webs, lateral rails are required for loading and unloading the reels with regard to the support belts; in a manner that, for example, an installation for the processing of two-ply material requires two pairs of reel-carriers, so that in each pair one reel can be in the operation mode, whilst the other reel is made ready to remain on stand-by to be spliced when the first reel runs out, with the entire installation taking up a rectangular area of, at least, 14 metres in length and 3.5 metres in width.        
In view of these drawbacks of the unwinding system in the processing of the aforesaid laminar webs of tissue, whereby the infeed reels rotate on a bed of motorised belts, attempts have been made to perform the unwinding by means of control cones that act on the mandrel of the reels, as is done in the sector of corrugated cardboard. However, all the tests carried out so far with regard to this have been unsuccessful due to the specific properties of the tissue material, namely its low tensile strength and its great flexibility which makes the cutting process difficult.
Besides the lack of success in the attempts to control the unwinding by means of cones acting on the mandrel of the reels, no progress has been made in replacing manual splicing, as the attempts at automation in this respect have also been unsuccessful, given their great complexity and high costs.